This application is 35 U.S.C. 371 National Stage filing of PCT/WO00/00412 filed Jun. 15, 2000.
1. Field of the Invention
The invention relates to an arrangement for irradiating a liquid with ultraviolet radiation, for controlling microorganisms in the liquid, comprising an enclosure of which at least part of a wall is at least partially transparent to ultraviolet radiation, provided with a gas discharge lamp, contained in the enclosure, and connecting means for connecting a supply voltage.
2. State of the Art
Arrangements of this kind are known in the art. They are used for the sterilisation of water and other liquids, for example in the food industry. The disadvantage of the known arrangements is that the supply voltages used are relatively high, which has been considered unavoidable until now, because a working voltage of a gas discharge tube is unavoidably high. The present arrangement obviates this drawback to a large extent and is according to an aspect of the invention characterized in that the enclosure moreover contains a converter or a transformer for transforming the supply voltage to a working voltage for the gas discharge lamp. The undeniable advantage is that the relatively high working voltage is present now only inside the enclosure.
A favourable embodiment according to an aspect of the invention is characterized in that the enclosure moreover contains a humidity sensor, arranged for switching off the supply voltage or the converter in case of leak or fracture, as a result of which the high voltage disappears in a split second and any safety risk is excluded.
A favourable application is according to another aspect of the invention characterized in that the arrangement forms part of a shower head. In this way, the Legionella problem is specifically addressed. It is well known that ultraviolet radiation effectively controls this bacterium. The present invention enables the water to be disinfected including the water that remains behind in the hose or shower head.
A favorable embodiment of the invention is characterized in that the shower head comprises a handle part and a head part and that the arrangement is coupled to the handle part and to the head part. It is possible then to use a relatively long gas discharge tube, which results in a long irradiation time for the water that flows in from the handle part side, while water that remains behind inside the shower head will be disinfected too.
A favourable embodiment of the inventive shower head is characterized in that the transparent part of the wall separates the shower head in two parts, such that one part is arranged for leading through water and the other part forms the actual enclosure. A favourable embodiment is characterized in that the transparent part is at least substantially flat or slightly convex. A further favourable embodiment is characterized in that at least part of the enclosure has a cross section which is of an at least substantially parabolic shape and is provided with a reflective layer, such that the water will be irradiated uniformly by substantially all ultraviolet radiation emitted by the lamp.
An alternative embodiment of the inventive shower head is characterized in that the transparent part is at least substantially tubular. A favourable embodiment is characterized in that the enclosure comprises an at least for ultraviolet light partly transparent tube, which is closed on one end and coupled to a housing on the other end, in which coupled housing the converter or transformer is housed. In this way, the enclosure becomes a module that can easily be installed or removed.
The invention also relates to a sanitary installation provided with an outlet, via which water becomes available for use, which outlet is provided with an inventive arrangement for irradiating the water. One may think of baths, Jacuzzi baths, saunas, steam baths, therapeutic baths, fountains and the like, where a contamination with the Legionella bacterium is imaginable.